how to proper use content_filter

[Paweł Grzesik]

Hi All,

I'm trying to understand how content_filter works. According to the
documentation I can create a simple script and use content_filter to send
an e-mail to it.

That's my config of master.cf:

proxy    unix  -       n       n       -       10      pipe
   flags=Rq user=filter null_sender=
   argv=/usr/local/bin/proxy -f ${sender} ${recipient}

smtp      inet  n       -       n       -       -       smtpd
  -o content_filter=proxy:dummy

So that's exactly the same as an example from to doc.

And now, my script is:

IO.popen("/usr/sbin/sendmail -G -i #{my_str}", "w") do |pipe|
    pipe.puts @mail_content
    pipe.close_write
end

Where my_str is a string of all arguments (sender and recipients):

ARGV.each { |recipient| my_str.concat("#{recipient} ") }

which is basically:
"-f sender@mymail user1@mymail user2@mymail"

The point os using it that way is because I noticed that bcc e-mail is on
that list and in the same way it's not in the mail headers. So I'm sending
that list of all recipients to the sendmail so I can put an e-mail again to
the queue without changing anything (and not losing bcc).

It works fine but when I change it to the Golang and I did mostly the same:

func sendMail(recipients string, maildata []byte) int {
  cmd := exec.Command("/usr/sbin/sendmail", "-G", "-i", recipients)
  pipe, err := cmd.StdinPipe()

  if err != nil {
    log.Fatal(err)
  }

  if err = cmd.Start(); err != nil {
    log.Fatal(err)
  }

  fmt.Fprintf(pipe, "%s", maildata)
  err = pipe.Close()

  if err != nil {
    log.Fatal(err)
  }
  return 0
}

So exactly like in Ruby I'm executing sendmail:
  /usr/sbin/sendmail -G -i (recipients from postfix ARGS)

but that does not work, on the logs I have:
  warning: -f option specified malformed sender: ...
and
  fatal: Recipient addresses must be specified on the command line or via
the -t option

I'm not really sure why is that. Why it works in Ruby and not in Go? I'm
calling it in exactly the same way and I have the same output on the
console. How I should handle it?

Can someone give me some hint?

Thanks,
Pawel